Motorists are topping off their tanks in preparation for Hurricane Matthew, leaving some gas stations empty on Tuesday and Wednesday in the Southeast, but industry observers said there should be plenty of supply so long as drivers don't panic.

Tamra Johnson, a AAA spokesman in Washington, said Wednesday the club received reports that stations in Florida were signaling that storage tanks were running dry by putting plastic bags on pump handles.

“There should be sufficient supply in the region if drivers don’t panic,” Johnson said. “Most supply problems during the storm will likely be a result of power outages or panic behavior.”

The Oil Price Information Service reported that “the hurricane will almost assuredly kill some demand. It is unlikely that it will do more than delay for a day or so some of the supply that goes to the region.”

No refineries are in the storm’s path unless it veers toward Canada, where key refineries in New Brunswick and Newfoundland are already in maintenance cycles.

“Drivers should expect to see some modest increases in price this week,” according to OPIS. “Gasoline margins for refineries are now well above where they have typically been in the fourth quarter of recent years, so once the storm is past, we may see prices recede.”

Dan Clemson, 64, hoped to fill up four gas cans at a Speedway station on U.S. 1 in Martin County. But he told the Treasure Coast Palm newspaper on Tuesday the pumps were dry.

Steven Dial, a reporter for WJXX-TV in Jacksonville, said stations across the coastal region were packed with motorists Tuesday night topping off their tanks before Matthew’s arrival. A Shell station he visited on Racetrack Road ran out of gas.